Respiration is a series of reactions in which energy is released from glucose glucose: A simple sugar made by the body from food, which is used by cells to make energy in respiration. Aerobic respiration is the form of respiration which uses oxygen. It can be summarised by this equation:
perturbation in Science. A small change in a physical system, most often in a physical system at equilibrium that is disturbed from the outside. Variation in a designated orbit, as of a planet, that results from the influence of one or more external bodies.
In astronomy, perturbation is the complex motion of a massive body subject to forces other than the gravitational attraction of a single other massive body. The other forces can include a third body, resistance, as from an atmosphere, and the off-center attraction of an oblate or otherwise misshapen body.